A magnetic carrier including a magnetic carrier particle having a magnetic core particle and a coating layer of an organosilicon polymer on a surface of the magnetic core particle, wherein the organosilicon polymer has the structure given by formula (T3) below; in .sup.29Si-NMR measurement of the THF-insoluble matter of the organosilicon polymer, the ratio ST3 of the peak area for the structure given by formula (T3) to the total peak area for the organosilicon polymer is at least 0.05; and in the roughness curve measured on the magnetic carrier particle, the mean width (RSm) of the roughness curve elements of the magnetic carrier particle, and the ratio (σ/RSm) to this RSm of the standard deviation σ of the width of the region where one period of a protrusion and a recess occurs, are in prescribed ranges.
R—Si(O.sub.1/2).sub.3  (T3) R in the formula represents a prescribed substituent.

There is provided a toner comprising a binder resin, a wax, a charge control resin and a colorant. As a result of gas chromatography analysis, a first total amount of components detected in a range of a peak detecting time of hydrocarbons having 5 to 9 carbons is 500 ppm or less in terms of styrene; a second total amount of components detected in a range of a peak detecting time of hydrocarbons having 10 to 18 carbons is 5,000 ppm or less in terms of styrene; and an amount of a component corresponding to a maximum peak of peaks of hydrocarbons having 10 to 18 carbons is 3,000 ppm or less in terms of styrene.

An electrostatic charge image developing carrier includes a magnetic particle and a coating resin layer that covers the magnetic particle and contains a silica particle, and a ratio of Si on a surface of the coating resin layer, determined by an X-ray photoelectron spectroscopy (XPS), is 6 atom % or more and 12 atom % or less.

A magnetic one-component developer includes magnetic toner particles containing a binder resin and a magnetic powder, and silica particles having a compression and aggregation degree of 60% or more and 95% or less and a particle compression ratio of 0.20 or more and 0.40 or less.

Provided is a toner having good endurance stability and good low-temperature fixability in high-speed printing, and having good resistance to the adhesion of printed paper. The toner is a magnetic toner having, on the surface of toner particle containing a binder resin and an ester compound as a releasing agent, inorganic fine particle “a” and organic-inorganic composite fine particle having a volumetric specific heat of from 2,900 kJ/(m.sup.3.Math.° C.) to 4,200 kJ/(m.sup.3.Math.° C.), in which a coverage A of the surface of the toner particle with the inorganic fine particle “a” is 45.0% or more and 70.0% or less.

Provided are cobalt ferrite particles having a micrometer-order average particle diameter and similar particle diameters. When a cobalt ferrite precursor is treated at a high temperature and a high pressure, an oxidation reaction is caused in the presence of a complexing agent, thereby obtaining intended cobalt ferrite magnetic particles.

Provided are magnetic particles (cobalt ferrite) having a micrometer-order average particle diameter and similar particle diameters. A cobalt ferrite precursor is heated in the presence of a sulfite, thereby obtaining intended cobalt ferrite magnetic particles.

The toner is a toner including a toner particle comprising a binder resin, a crystalline material, wherein, when a ratio of an area occupied by the crystalline material in a toner surface observed with a scanning electron microscope after ruthenium-staining the toner under a specific condition (1) is represented by S.sub.1 (%), a ratio of an area occupied by the crystalline material in the toner surface observed with the scanning electron microscope after ruthenium-staining the toner under a condition (2) is represented by S.sub.2 (%), and a dispersion diameter of a plurality of domains formed of the crystalline material on the toner surface observed with the scanning electron microscope after the ruthenium-staining the toner under the condition (2) is represented by R.sub.2 (nm), the following expressions (1), (2), and (3) are satisfied.

[00001]$\begin{array}{cc}0.0\le S_1\le 0.5& \left(1\right)\\ 1.0\le S_2\le 10.0& \left(2\right)\\ 20\le R_2\le 200& \left(3\right)\end{array}$

There is provided a toner containing: a toner particle containing a binder resin, a releasing agent, and a colorant; and an iron oxide particle present on a surface of the toner particle, in which the iron oxide particle has a surface containing a compound having a specific structure.

A toner comprising a toner particle including a binder resin, wherein the toner is such that (1) when a powder dynamic viscoelasticity measurement method is used, a measurement start temperature is set to 25° C., and a ramp rate is set to 20° C./min, on a curve of a storage elastic modulus E′ (Pa) where a temperature (° C.) is plotted against an abscissa and the storage elastic modulus E′ is plotted against an ordinate, a temperature at a time when the E′ at a start of a measurement has decreased by 50% is from 60° C. to 90° C., and (2) a load at a yield point of a displacement-load curve which is determined by a nanoindentation method and where a load (mN) is plotted against an ordinate and a displacement amount (μm) is plotted against an abscissa, is 0.80 mN or more; and a method for producing thereof.